Bitters Confluence is named for its location straddling the junction of the Bitter and East Bitter Rivers. While almost every person and piece of cargo in Delicos will pass through the highways and waterways of Bitters at least once, the town itself remains small. The town lives off catering to passersby, both in terms of providing hospitality and hosting a number of cheesy tourist traps.
The other primary draw of Bitters Confluence is the ancient abandoned military base, a relic of the ancient time when humans found such things necessary. Now the somber ruins are a popular place to search for ghost-type pokemon.
Oh, and the Swamp Gym can be found there, for the weirdos who are into that kind of thing.